More Pipeline GUI Improvements

 - You can now add multiple files at once.
 - You can remove content using the delete key.
 - Tree items are now always alphabetical.
 - We now default to Consolas for the output window.
 - The property grid defaults to all fields expanded.
 - Better handling of platforms in EffectProcessor.

![pipe3](https://cloud.githubusercontent.com/assets/103522/2935667/cde94448-d821-11e3-9bb2-a23ab6da75fb.png)